[MacDV] Re: iMovie HD bugs

[Matti Haveri]

[continued from the previous message]

4. In iMovie HD 5.0.1 exporting via the expert settings as a DV 
stream deinterlaces video and loses timecode.

5. iMovie HD 5.0.1 distorts interlacing when importing and rendering 
4:3 MOV or DV files to a 16:9 DV Widescreen project

a) If the imported 4:3 .mov or .dv file has ONLY its High Quality 
flag enabled, then iMovie HD 5.0.1 distorts the interlacing lines.

  b) If the imported 4:3 .mov or .dv file has deinterlaced playback 
setting (i.e. High Quality + Single field flags or NO flags at all), 
then iMovie HD 5.0.1 deinterlaces the imported file.

I consider both a) and b) bugs because the footage is either 
distorted or deinterlaced behind the user's back!!

The imported clip's playback setting should be just a PLAYBACK 
setting. It should NOT alter the behaviour of the .mov or .dv file in 
any other way!!

(Unlike .mov files, the .dv files can't save the playback quality 
setting but applications like Toast and MPEG Streamclip store the 
playback quality info in the .dv file's resource fork).

6. iMovie now deinterlaces also saved PICT frames. iMovie 4 saved 
PICT as interlaced and deinterlaced JPEG. Sometimes it was handy to 
save interlaced PICTs so that they could be reassembled as a new 
interlaced video sequence.

Workaround: export interlaced still images or image sequences from 
QuickTime Player Pro.

iMovie HD also uses new routines when importing a still image and 
when saving as a still frame. iMovie HD now saves NTSC 720x480 
rectangular pixel video as a 720x528 square pixel image.

I wonder what the logic behind this new behaviour is. Maybe Apple 
wants to save the still images to a resolution which doesn't have to 
be upsampled in any direction when re-importing it back to iMovie 
(640x480 must be upsampled and padded to 720x480)?? FWIW, the chosen 
NTSC 720x528 is near the 720x540 oddball resolution (or 704x528) 
which should be avoided because it needs vertical scaling that 
distorts interlacing.

Apple's still image import and export routines now _almost_ correctly 
preserve the aspect ratios when converting rectangular video pixels 
to square pixels.

<http://www.iki.fi/znark/video/conversion/>

<http://www.sjoki.uta.fi/~shmhav/iMovie_HD_bugs.html#stills>

...More bugs, info and examples are at:

<http://www.sjoki.uta.fi/~shmhav/iMovie_HD_bugs.html>

...sigh ...the quality control in iMovie 3-5 has been bad... iMovie 1 
and 2 were OK.

>  do you have HD-related requests?

I have mainly used only plain 4:3 projects.